The present invention relates generally to personal computers and more particularly to keyboards designed for use with personal computers. Still more particularly, the present invention relates to a hand-held, self-contained test unit that connects directly to a 101-key type MF-II enhanced keyboard designed for use with personal computers.
The manufacture and sale of personal computers is increasingly a competitive business. Manufacturers strive constantly to design and build personal computers with ever greater processing capabilities and features at lower costs. At the same time, however, stringent quality control is absolutely essential. Excellent processing capabilities and numerous features are more than offset in the marketplace by a reputation for poor quality control. Thus, manufacturers endeavor to provide the best possible quality control at the least possible expense for each part of the personal computer system.
The keyboard is an essential part of a personal computer system, receiving keystrokes and passing information to the system unit about keys being pressed or released. Its operation centers around a microcontroller, typically an Intel 8042 or 8742 microcontroller or equivalent device from another manufacturer. The microcontroller executes five basic functions within the domain of the keyboard. The first of these five functions involves the performance of certain internal tests, including the generation of a power-on reset (POR) signal and a basic assurance test (BAT), which checks the keyboard microcontroller, read-only memory (ROM), and random access memory (RAM). The second function involves assuring the limited programmability of certain keys. The third function relates to conducting key position scanning and recording. The fourth function involves serial data communication with the system unit, the fifth function relates to the typematic function of the keys, and the sixth function relates to LED status indication. The ability of the keyboard microcontroller to execute each of these functions is critical to the operation of the keyboard and the personal computer as a whole.
Some personal computer manufacturers make their own keyboards; others buy keyboards from another manufacturer and package it as a part of their computer products. In either case, quality control of the keyboard itself is an important consideration. Keyboard manufacturers must verify that the assembled keyboards are in good working order before being packaged with their own computer systems or sold and shipped to another manufacturer. Those purchasing keyboards from another manufacturer must verify that the keyboard is received in good working order before packaging it as a part of their own system.
Typically, keyboard testing has involved connecting the keyboard to a personal computer, booting up the computer, loading a diagnostics program, and checking to see if the keyboard operates as expected. Such testing, however, is inefficient for several reasons. First, dedicating entire personal computers solely for the purpose of testing keyboards is expensive. Second, the process of connecting a keyboard to a personal computer, booting up the computer, and loading the diagnostic software is time consuming. Third, a personal computer is bulky and not easily transported, requiring that a particular space be dedicated for the computer equipment and that the testing process be centered around the area containing this equipment.
Hence, it would be advantageous to devise a keyboard test unit that is simple, compact, and relatively inexpensive and yet capable of fully testing the functional capabilities of a keyboard.